Process control systems, like those used in chemical, petroleum or other processes, typically include one or more centralized process controllers communicatively coupled to at least one host or operator workstation and to one or more field devices via analog, digital or combined analog/digital buses. The field devices, which may be, for example valves, valve positioners, switches and transmitters (e.g., temperature, pressure and flow rate sensors), perform functions within the process such as opening or closing valves and measuring process parameters. The process controller receives signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals that are sent over the buses or other communication lines to the field devices to control the operation of the process. Information from the field devices and the controllers may be made available to one or more applications executed by the operator workstation to enable an operator to perform desired functions with respect to the process, such as viewing the current state of the process, modifying the operation of the process, etc.
Typically, a process control system operates within a business enterprise that may include several process control plants, component and/or service suppliers and customers, all of which may be distributed throughout a large geographic area or, in some cases, throughout the world. The process control plants, suppliers and customers may communicate with each other using a variety of communication media and technologies or platforms such as, for example, the Internet, satellite links, ground-based wireless transmissions, telephone lines, etc.
Of course, the Internet has become a preferred communication platform for many business enterprises because it provides an established communications infrastructure, which tends to minimize the communication infrastructure costs for an enterprise. Additionally, the technologies used to communicate information via the Internet are well-understood, stable, secure, etc. Further, the increased geographic distribution of typical enterprises in combination with the increased degree of automation and, as a result, the need to have fewer more productive or efficient employees, has resulted in the development and proliferation of highly-portable, full-featured communication platforms. For example, personal data assistants (PDAs), cellular telephones, pagers, notepads, tablets, laptop computers, wearable computers and other communication platforms and devices (many of which are currently available as web-enabled devices) are currently used to leverage employees throughout large business enterprises, many of which are distributed across large geographic areas.
The proliferation of portable communication platforms and devices has been accompanied by the development and proliferation of improved operating systems such as, for example, Windows XP®, Microsoft.NET™, etc. and communication protocol improvements such as, for example, Ethernet, voice over Internet protocol (IP), streaming video, etc. In addition, improved information or data transfer and central data storage devices and techniques such as those provided by, for example, extensible markup language (XML), simple object access protocol (SOAP), universal description, discovery and integration (UDDI), etc., improved orchestration systems or servers such as, for example, Biztalk®, improved programming languages that are execution platform insensitive such as, for example, Java, and a host of other improved communication and/or data management tools, standards, protocols, programming languages, etc. have developed along with the proliferation of portable communication platforms. Most, if not all, of these communication and/or data management tools are currently used in conjunction with wireless communications, particularly in situations where the communication and/or data management tools are operating, at least in part, in conjunction with one or more portable communication devices.
Each process control plant within an enterprise may include one or more process control systems as well as a number of other business-related or information technology systems that are needed to support or maintain, or that are complementary to, the overall operation of the process control systems. In general, the information technology systems associated with a process control plant may include manufacturing execution systems such as, for example, a maintenance management system and may also include enterprise resource planning systems such as, for example, scheduling, accounting and procurement systems. Although these information technology systems may be physically located within or near a plant, in some cases a few, or possibly all, of these systems may be remotely located with respect to the plant and may communicate with the plant using the Internet or any other suitable communication link using any desired combination of wireless and/or hardwired communication media and techniques.
Each process control plant within an enterprise may also include user-interactive applications that may be executed on a server or workstation that is communicatively coupled to one or more servers, workstations, or other computers that coordinate or perform the activities of the process control system within the plant. Such user-interactive applications may perform campaign management functions, historical data management functions, asset management functions, batch management functions, etc. In addition, each of the process control systems may include process management applications that may, for example, manage the communications of and provide information relating to alarm and/or other process events, provide information or data relating to the condition of the process or processes performed by the process control plant, provide information or data relating to the condition or performance of equipment associated with the process control plant, etc. In particular, process management applications may include vibration monitoring applications, real-time optimization applications, expert system applications, predictive maintenance applications, control loop monitoring applications, or any other applications related to controlling, monitoring and/or maintaining a process control system or plant.
Still further, a process control plant or enterprise may include one or more communication applications that may be used to communicate information from the process control system or plant to a user via a variety of different communication media and platforms. For example, these communication applications may include e-mail applications, paging applications, voice messaging applications, file-based applications, etc., all of which may send information via wireless or hardwired media to a desktop computer, a laptop computer, a personal data assistant, a cellular phone or pager, or any other type of device or hardware platform.
Paging applications are often used to convey process control alarm or alert information to portable communication devices, such as cellular pagers, cellular telephones, PDAs and laptops equipped with a cellular or other wireless communication interface, etc. Generally speaking, alarm or alert information is usually generated by a process control system and conveyed to one or more persons (via their portable communication device or devices) associated with the operation of the process control system in response to the occurrence and detection of certain event conditions within the process control system. For example, an impending or actual failure of a field device, an out-of-range loop parameter or other control parameter, etc. may result in the generation and conveyance of an alert or alarm to a field technician, plant operator, and/or any other person associated with the affected process control system.
With known alarm or alert paging systems, process control system users or operators typically interface with a configuration tool, which may provide an intuitive graphical user interface or the like, that enables definition of events or conditions that will result in the reporting of one or more alarms, alerts or other conditions to one or more users. In addition, during configuration, a system user or operator may use the configuration tool to define the personnel who receive certain alarm or alert information and in what manners the alarm information should be delivered to the personnel receiving the alarm information. In particular, the system user or operator can typically define alarm routing procedures that are based on simple static routing schedules or, if desired, based on one or more rules, which may vary the routing of an alarm or alert based on the type and/or severity of the alarm or alert, the identity of the person or persons to whom the alarm or alert is to be conveyed, the time of day or current work shift, or any other desired parameter or combination of parameters.
Of course, a single event or condition within a process control plant may trigger multiple alarm or alert messages, some or all of which may be conveyed to a particular person or to a particular group of individuals via a paging system. Further, in some cases, a single alarm or alert may be communicated to one or more individuals via more than one communication link and receiving device. For example, an alarm may be transmitted via a paging system to a cellular pager and a cellular phone that are both associated with a particular person.
Many paging systems are one-way systems in which alarm or alert information is conveyed via a cellular pager or phone. In one-way systems, the pager or phone receiving the message can, in some cases, display a simple textual message that provides the user with important information about the alarm or alert. For example, the message may contain location information (i.e., a physical location within a process plant), information that identifies a particular affected field device or unit, control loop parameters, etc. associated with the alert or alarm. However, one-way systems do not enable the user to respond to an alarm or alert received via the pager or phone using the phone or pager keypad. Instead, these one-way systems require the user to physically travel to a location within the plant associated with the alert or alarm, to place a phone call to another person that can travel to the location and/or to log onto a network coupled to the process control plant via a laptop or remote user terminal to provide a response to the alarm or alert to the process control system that generated the alarm or alert.
Some existing paging systems enable limited two-way communication between a portable communication device (e.g., a pager, cellular phone, PDA, etc.) and a process control system. These two-way systems typically send an enumerated menu of possible responses along with alarm or alert messages to the portable communication device. When the user receives an alarm or alert via their portable communication device, the information pertaining to the alarm or alert (i.e., an alarm or alert message) is typically displayed along with a limited menu of possible responses associated with that alarm or alert. To respond to the alert or alarm, the user may invoke one or more of the possible responses by entering the numbers or digits via a keypad on the communication device that correspond to the desired response or responses.
With most two-way paging systems, responses to alerts or alarms made via a portable communication device are returned to the process control system that issued the alert or alarm via standard paging communication systems and are typically in the form of a simple textual reply message (e.g., in the form of an ASCII string) and/or a numeric value. In the case of a textual reply message, the reply message is typically displayed to one or more system operators, who may, if necessary, respond to the message by taking some action. In the case of a numeric value, the numeric value may be automatically used by the process control system by, for example, writing the value to a control strategy to automatically invoke an appropriate response.
Unfortunately, existing two-way paging systems are very limited in their capabilities and flexibility. In particular, existing two-way paging systems provide very limited monitoring functions that typically only enable the monitoring of conditions or events within a particular process control system. Accordingly, existing two-way paging systems typically do not enable the monitoring of conditions and events on an enterprise-wide basis. In addition, alert or alarm information conveyed by existing two-way paging systems is typically limited to simple textual information, thereby significantly limiting the ability of a field technician, system operator, or any other person associated with the process control system to diagnose, troubleshoot and/or effect a correction in response to the alert or alarm. For example, diagnosing a failed field device or a problematic control loop may require graphical information, image information, or information that is more complex than a simple text message. Still further, with existing two-way paging systems, responses sent by the portable communication devices (e.g., pagers, cell phones, etc.) are typically limited to simple text messages and/or simple numeric values, thereby significantly limiting the ability of the person responding to an alert or alarm to effect an appropriate correction from a remote location.